This invention is in the nature of an improvement over the structure disclosed and claimed in prior U.S. Pat. No. 3,824,047, issued to Hugh L. McDermott. In the structure disclosed in U.S. Pat. No. 3,824,047, a pair of mounting members are made each in one piece of resilient material, being formed to provide an elongated body that engages the radially inwardly facing bottom of a recess, and in-turned ends which engage the outer cylindrical surface of a rotor to provide bearing means for the rotor. In some instances, material having the resilient qualities needed for biasing the ends of a mounting member into sliding engagement with a rotor is not the best bearing material for a rotor of a given material. Thus, in some cases, early and undue wear occurs, either on the rotor or on the mounting member.